Through Hell and Back
by Mentalkallan
Summary: A new blond-haired recruit arrives on the UAC Mars base just in time to see everything go to hell. Mega Man X/Doom 3 Crossover. Rated M for violence, language, and slight BL in later chapters- but that's not my focus.
1. Arrival

The Union Aerospace Corporation is the largest corporate entity in existence. Originally focused on weapon and defense contracts, new ventures have expanded into biological research, space exploration, and other scientific endeavors.

With unlimited funds and the ability to engage in research outside of moral and legal obligations, the UAC controls some of the most advanced technology ever conceived…

He huffed as he gripped his injured side, tilting his torso away from the incoming shot. He didn't even see friend or foe anymore. Hell, through the gnawing pain, all he could see were light and dark blurs…

Hell…

His blond ponytail was drenched with sweat and blood, matted to the back of his cracking armor. His eyes narrowed at his target, the handgun snapping out a quick rhythm. Finally the 'foe' fell, slumping into a grotesque heap in the darkness. His eyes flew around the room, somehow making out the telltale teal blur in the enveloping, cold dark of the hall. He leapt towards the repair kit with gusto.

As the kit worked on knitting his seeping side together, he let the sedative take him away for a while…back to this evening…

Hell…

He didn't like it as soon as he set foot on it.

* * *

><p>The Mars Base was simply so boring. Being assigned to that dungeon was the worst thing the government could do to you aside from dishonorably discharging you, but the bionic human honestly didn't give a flying fuck. In fact, he was rather excited.<p>

An old war friend of his had been assigned to the base a long time ago, and the idea of seeing him again was refreshing, and made the long journey and lame assignment tolerable. The councilor across from him on the space transport coughed as he lit a cigarette, as the marine let the cabin fill with stale, choking smoke. No matter how many times the councilor and his bodyguard shot glares, he'd simply smile back through his visor and light another. Certainly took the edge off of leaving his old life.

He slipped off the transport after an especially rocky landing, stepping off onto the metal catwalk and proceeding to receiving—including those invasive bio-scans. The blond half-grinned as the folks at the machine gawked at just how black his lungs were. That is, until they confiscated his packs of cigarettes and insisting that the UAC was a 'smoke free' facility.

Well, fuck it…

That was an exceptional mood ruiner. He half-stomped to reception, tossing his things beside the desk unceremoniously. The receptionist gazed at him half-heartedly as he punched him into the system, shoving a security PDA in his direction. He groaned. So that's what he was doing. Guarding a military base where the only threat was overworked, unarmed civilians.

The scowl was deep- set on his face until they told him his first order: to go see the commander in charge. They sent another Sergeant, X, to train under Sergeant Kelly and fill his place until he returned from his extended vacation. The new marine was heading to Command briskly, footprints echoing in the cold halls, when suddenly he heard raised voices.

What appeared to be an aging man, bald as an egg and blind in one eye, was returning heated words to the councilman, his eyes narrowed.

"I'm here because there seems to be some very serious problems," The councilor stated dryly, eyes equally as narrowed at the head scientist.

"Oh really? Do I need to remind you of the groundbreaking work that we're doing here? " The doctor spat back, growing irate.

"No. But I've been authorized by the board to look at everything."

"The board authorized you? Hmm, the board doesn't know the first thing about science," the scientist turned, leaving a pregnant pause in the air, and the marine felt vaguely like he was choking. "All they want something to make them more money, some…product. Don't worry; they'll get their product. " For a split moment, the voyeur saw a ghost of a smile across the senile doctor's lips.

"After how many accidents? Tell me, Doctor Betruger… why are so many workers spooked, complaining, requesting transfers off Mars?"

"They simply can't handle life here. They're exhausted and overworked. If I had a larger, more competent staff and a bigger budget…these few accidents could have been avoided." Betruger replied with spite, the last few words hissing through his teeth.

"I'm afraid you'll get nothing more until my report is filled with the board. I will need full access Doctor Betruger, Delta included. I won't have any difficulty doing that, will I?" The councilor bristled at the very mention of Delta. The idea of going to –that- lab was unpleasant to say the least. He had only heard horrible stories of the place, and it was the center of most of the complaints against Betruger and the United Aerospace Corporation.

"Only if you get lost Swann," This time, Betruger really did grin. It was a sickening, false-pleasantry sort of smile. "Just stay out of my way. Amazing things will happen here soon. You just wait." With that, Betruger hastily stomped out of the room, his eyes flying to the eavesdropping Marine. For a moment, the man felt as if his Blind Eye's haunting gaze was piercing him through his chest.

Hastily he turned, the blond ponytail swiping at the air as he walked off, bionic joints creaking. He followed the signs he should have followed fifteen minutes ago, and as he was passing by the communications station near Command, he overheard the conversation with Delta Labs.

"We need another security team in Delta," a tired voice stated, emerging from the high monitor above their heads. The face the voice belonged to looked beyond weary, brow creased heavily and his face set in a serious frown.

"I'll put your request in." The marine stated, his voice dry as if he didn't take the man seriously. Apparently this happened a lot.

"…Thank you." The civilian replied, though from his furrowed brow, the marine imagined he was anything but thankful. He obviously doubted the man at the Comm. Link, and for good reason. As soon as the communication flickered off, everyone in the immediate vicinity burst into boisterous laughter.

The blond shook his head. Just what kind of messed up place was this? Though he did see some reason in the laughter; after all, what was there to be afraid of? He sighed deeply as he entered the main marine facility, when all he saw was bright green eyes and a smile.

"Zero! There you are! It's been forever!" The brunette shouted boisterously, lunging forward to greet him. His military steel façade was thrown away the instant Sergeant X set eyes on the blond, resulting in rather blatant, blank, and bewildered gazes by his men. The bionic sergeant reached out and grasped his fellow half-man by the hand, shaking vigorously, and pulling the soldier into a friendly embrace. He was a touch shorter than Zero, and was quite a bit softer looking. He wasn't designed for war, after all.

For one, X was much slimmer and slightly shorter than Zero, his build much more delicate and reinforced with much more armor. The armor looked entirely out of place on the thin frame, but it seemed to have held up quite nicely during the Sergeant's long assignment. His eyes, Zero thought, were always a bit innocent looking, and it always seemed to be the last thing on X's mind to hurt someone. That's how it was on Earth, anyway, and it seemed to Zero like as soon as X's eyes were off him, they grew cold and hard.

It worried him.

"Sorry to cut the reunion short, Sarge-" An irate soldier spoke, "But that missing scientist is still kind of missing." X gained a blank look on his face, and it suddenly lit up as he remembered. "Right! Zero! Since it's your first time around here, we're going to go look for this guy in the abandoned communications facility in the subsystem. It's what supports everything around us, if you didn't know already." X grinned, starting to step back into the labyrinthine halls and tugging the new bionic marine along with him. Zero had the faintest feeling he would quickly become lost without the Sergeant leading him along.

They had to go down a dingy elevator into even dirtier, older facilities, rusted red and gray from overuse and aging. "Come on, get your gear." X said impatiently, the security man behind the glass punching a few keys to open the blast screen between them and the armor and weapons. Zero practically threw everything on; wanting to get something between him and the stale, almost tense air. The armor felt at home on his body. The pistol at his side, however, was new. He sat through the radio test as they cleared them through into the subsystem, wandering down even more dirty halls. They passed people who looked like they hadn't slept in days; irate maintenance men that glared at the two security officers.

"…Why does everyone seem to look at us so contemptuously, X?" Zero asked aloud, his eyes flying to his smaller friend. X's endless smile seemed to fade into seriousness.

"Alright…do you know why no one wants to be assigned here, Z?" He asked seriously, his verdant eyes chasing up to Zero's aquamarine, "Do you know why there are so many people on waiting lists to get off this rock? Why people here look like they haven't slept in years…?"

Zero hadn't even opened his mouth and still X continued, "There's something –wrong- with this place, Z. Nothing on earth is like this facility…both in terms of amazing technologies…and…just… just don't let this place get to you, Z. Focus on your job. You'll be back on earth before you know it."

Zero quirked an eyebrow at the Sergeant. It wasn't like X to be so roundabout. Wasn't like him to stop smiling. While they were heading towards the airlock, they were nearly stopped by another maintainance man, who suddenly changed his mind about telling the two security officers why exactly they didn't want to find the missing scientist. Every second made Zero more unsure. Every pair of eyes watching him made him more unsure. Whatever was happening here, it was sure to be nothing like anything Zero had ever experienced. It was his last thoughts before the airlock opened, revealing the dusty, blustery surface of Mars.

Crossing the Martian surface to the old Comm facility was easy enough, panting from a brisk run across a bridge, an oxygen high from his tanks and a bit of dust across his armor was all that indicated he had been outside at all. The facility was nearly completely dark, the only noise a rhythmic thrum from the computers, making it sound like the walls were breathing on bated breath.

X flicked on his flashlight, leading Zero up a few stairs and around a bend. He stood at a locked door, patting his person somewhat frantically. "Aw, crap! I forgot my PDA back at Marine Command…" He snapped softly. "Here, this place is General Access, I'm sure you can open up the door with yours." He said, indicating the door and stepping back.

Detecting the PDA and the clearance, the door shot open with an alarming sound, and a human scientist yelped in alarm as his eyes flew to the two marines. Fingers ran through his short, black hair, fever in his eyes and sweat glazing over his skin.

"No! Please! You must let me get this communication out," He whipped back to the communications control panel, shivering, clearly either traumatized or out of his mind, "They have to be warned while there is still time. I can't let..." He trailed off as he was nudged away from the panel by Zero's gentle hand.

"Listen—" He chuckled, "Buddy—you gotta stop and come back with us—"

"You don't know what I've seen!" The scientist shrieked, pushing the marine off of him, "You can't possibly understand or comprehend. The…" he paused, swallowing. He was apparently hesitant to say what he was about to say.

"The Devil is... real…I know..." He trailed off, deep sorrow creasing his face, "I know because… I built his cage."


	2. Mars City

A split second ticked by, like a pin hitting a steel floor. "I'm getting abnormal readings.." A scientist seemed to mutter from the computer speakers, before a loud alarm crossed the base. The scientist screamed at the camera labeled 'Delta Labs Portal' as fire consumed the equipment, power lines bursting and scientist's screams bouncing from the speakers into the empty halls of the communications facility.

"What the hell's happening?" X finally demanded of the practically melting scientist, whose hands flew up to his face in horror as he screamed. "Gh-God save us—" He cried out, as the lights knocked out into darkness.

X bristled, reacting as reasonably as anyone would. His flashlight snapped on, highlighting the terrified scientist's face. "I ask again" He spoke evenly, "What—" He wasn't sure when the ground came up to meet him, but he grunted, glancing around at the floor, alit with fiery symbols. Inscribed for an instant in the room, then vanishing as if a bad dream. Screeches filled the darkness, the wavering flashlight beam snapping around the room, searching for something, anything.

Zero was frozen, his bright eyes wandering the room, artificial heart pounding in his chest as a fiery apparition entered the chamber, a grin flashing across its terrifying teeth as it dove for the scientist, jaw agape.

The shaking flashlight beam focused on the scientist, shaking as the scientist stood again, his empty eyes gazing at Zero foreignly.

"…Sir?" Zero asked softly, before getting a harsh swipe to the face and a snarl. Three snaps of his pistol, and the creature fell like a brick. No longer human, but something wearing a human skin. The soulless creature disinigrated to ash before the bewildered eyes of the marines, not a word was uttered between them.

The frantic screaming over the radio snapped X back to reality as Zero tended to his face, groaning. That bitch's nails hurt. He could only contemplate upon how the Doctor was perfectly okay not two seconds prior, and now he was pale and dead, brains leaking over the steel catwalk.

"We don't know what we're up against! All marines, fall back to Marine HQ for a rendezvous! If you are unable to reach Command stock up on ammo and supplies and set up a Command post there!" X yelped into his microphone, the steely façade thrown up quickly.

It was all happening so fast, and yet so slowly.

Tonk.

The sound of the automatic door lock clicked as both marines snapped their heads in its direction.

Demonic chatter filled the area as gunfire rang out, Zero backing onto another platform and X slamming himself onto the wall. X readied his pistol for whatever came out that door. When it did, he hesitated. The creature wore the face of a friend of his, someone he had spent a lot of time with. The marine let out a gurgling moan, raising its own pistol at X's head slowly. When X finally aimed his own pistol and tried to squeeze the trigger a shot was through the side of the dead marine's head.

"X-" He heard an angry scold from his left, the shaking Sergeant glancing to Zero, "When did you become a Private again!"

There was another stifling pause in the air as the automatic door proceeded to try and squish the ex-marine's head to paste.

"There's no time to think. We need to move to HQ- Now!" Zero shouted, though it was more to himself than to the shivering commander. X merely nodded, barking more orders into his comm. Unit as they ran down the hall. The hall was littered with pale, gray, groaning humans that tried to swipe at them with their hands- just like the Doctor. They fell with a few bullet holes through them, but they seemed to fall faster if shot through the head. Now, X was sporting scratches to match Zero's.

X counted it as a miracle that the airlock was still functioning properly with all the power fluctuations.

They ran back outside and through the airlock. They were back in Mars City proper. The two marines realized in horror that the staircase was taken out that lead to Marine HQ. X hissed out a sigh as he reloaded his pistol, shaking his head. It had been nonstop killing his own possessed men, demonic chatter on their radios as the once-men fired blindly at the two bionic marines.

"Well, I don't know where the hell we can go…" He uttered, frustrated. His eyes trained on the blocked way out of the airlock area. "Gods…"

"Sarge! Sarge is that you!" came a loud whisper from the shaft above their heads. "Sarge! I thought everyone was dead...thought for sure I was the only one left alive—here!" He let down a ladder, leading into the air shafts that ran through the mars underground facility.

"It was like a shockwave…like the entire base was rocked at once…" he whimpered, "The shaft should take you guys past the blockage. I'd come with you, but…I'm not going anywhere. It's...safe here," He uttered, curling back into his corner, intent on keeping his ground in the deceptively safe tiny room.

Crawling through the cramped shafts was hard and awkward, the two of them travelling in silence, with the only chatter coming from their frantic radios. X constantly repeated his orders into the chatter, and Zero was shivering from adrenaline as they finally reached someplace they could drop down into.

The winding halls became less daunting with two, one knowing his way though the long halls. It wasn't until they walked into a hall that things became complicated. X growled softly. It hadn't been fun putting down his men-turned-monsters, and now the most direct route was blocked by fire. Zero shook his head, and began to head down the other path. X was about to follow when he saw a flash of shadow out of the corner of his eye.

His hand reached for Zero's shoulder, stopping him short. "Z." He spoke, punctuated by a throaty, distinct screech. It was human…yet not, somehow. It even caught Zero's attention as he turned to fix his eyes on the pipelines where X's gaze was transfixed.

A claw reached out, followed by a matching arm, another following to grasp the pipe as well, pulling an eerily bony, slim, humanoid form out of the small crevice. The creature seemed unaffected by the flame as it turned its head to snarl at the two marines. X seemed transfixed by its sixteen, jet-black, beady eyes, while Zero eyed the bloody claws that seemed to create flame before them, drawing one massive claw back, and tossing it. The ball of flame landed someplace behind them, but that seemed to be the least of their troubles as it lunged with surprising agility, screeching.

X surprised even himself when he blasted two pistol shots into its skull before it could begin to tear his face off. Silence left the air heavy and thick as they examined the strange creature. Vaguely humanoid, not affected by fire…if Zero didn't know better, he'd say the thing was an alien- he then spotted a window that revealed a zombie gnawing on a dead man's arm. He grit his teeth. Maybe the gray thing was demon of hell, raising their comrades and taking their souls away. Certainly seemed like something the fiery deeps would spew out.

Zombies littered the halls in front of them as X and Zero made their way to Marine HQ, depleting the two marines of ammo and weapons. They ocassionally invaded a storage cabinet, picking up whatever ammo and weapons they could. This ordeal became more perverse the second the chatter began to fall silent, all marines dead or hiding, trying to hold their positions from their own friends and whatever else the foreign enemy decided to throw at them.

They certainly didn't mind throwing unhuman demons at them. A chuckle seemed to echo through the halls, and Zero instantly recognized the voice. It seemed so familiar, yet distant. The identity seemed to just slip his grasp as he was brought back to reality by X stopping in front of him, seemingly taken with whatever was in front of him.

Zero glared hard at the back of X's unarmored head as if asking what the hell he just stopped for, when X simply raised a pointed index finger, his eyes wide in horror. Everything Zero had done, not training, not combat could prepare him for this gruesome sight.

One of the gray, leathery creatures from before was claws-deep into the gut of a zombie, pulling out entrails to its dripping, gory maw. It chewed a moment before swallowing, then suddenly seemed to catch on that it was being watched. It rushed to the glass between the marines and it, smearing human blood on the blast screen, screeching loudly and littering bloody particles on the glass.

X nearly retched, tasting bile as the creature climbed up and over, as if looking for a way inside, while the zombie it was eating from stood and shambled elsewhere, leaking parts and fluid everywhere. They stood, frozen a moment, the two of them slowly linking gaze, unsure of what to make of what they just saw. They had found a nifty hand-held machine gun, but that hardly seemed to quell the idea of the gruesome fate they had should they fail.

Silence fell over them like a dark curtain as they pressed on, finally meeting the ruins of Marine Command. Bodies of fallen marines were everywhere, and the stench of them was overwhelming, like brimstone and burning flesh… those demonic things were here, the smell and the mess the bodies were in telltale signs. Zero gagged a bit. He never could get used to the smell of burning flesh.

The door between them and X's PDA was hopelessly jammed, even with the both of them attempting to yank it open by force. Besides, the computer controlled turret at the end of the hall would probably fill them with holes before they could even dream of getting close. X shook his head. There had to be another solution. The communications terminal. He could certainly update theit security clearance from there. It was unlocked and open open as X sat down at it, punching keys and buttons to update the security codes of Zero's PDA to allow them to go into the administration offices. As he pressed enter, X could have sworn he heard a shuffling in the hallway.

"Administration?" Zero whispered angrily as X stood, moving to the armory across the hall. "Give me one good reason why we shouldn't stay here at Marine command!" He growled as his commander led him across the hall, and punched a code to get into the armory. X tossed him a shotgun, along with shells and bullets for his pistol.

"Don't you want to get to the bottom of what just killed all my men? The last thing we need is to split up, Z. Bad idea. And as your commanding officer, I want you to come with me…" He eyed some odd blue cells, appearing to be plasma, before pocketing them. "That's an order, Z."

The communications console suddenly lit and spoke, surprising both of them into a jump. The cheery, female voice informed them of an incoming call from the Delta Complex. Doctor Betruger himself greeted them. Rather than the ill mood he seemed to be in when he and the Councilor spoke, he seemed to be rather cheery. "Impressive Gentlemen," He spoke, "It's good to see you alive Sarge, but we've got urgent business to attend to."

X merely glanced at the gore surrounding them, biting back a smartass remark. "Yes. Do we have a plan against these invaders, Betruger?" The doctor merely nodded, before continuing.

"Yes, a small squadron is on their way to the Comm tower to see if they can't get a distress signal to earth. They're in Alpha Labs now, but they'll need you leading them, Sarge."

Zero bristled. There was something about that Betruger that set him off. His eye or something. He was just too downright creepy. His cheeriness despite the gore surrounding them. Something was off. It seemed to bother him greatly as he followed his commander into the halls to Administration.

"Don't you think that was a bit odd?" Zero finally asked after X downed another Imp. X looked at him with an incredulous sort of look.

"Is this really the time, Z?" X asked, a bit urgently, his green eyes glaring hard into Zero's blue ones.

"Well, it is if I think your leader's nuts. We shouldn't trust him," Zero growled, begrudgingly as they trudged through the halls. Everything was coated in a thin layer of splattered and dried blood.

"Don't be absurd. Doctor Betruger has been on this facility since before I was here. Honestly..." X uttered, unbelievingly, "He's always been a great man and an earnest worker..." his voice trailed off, mind wandering to the incident the doctor was in.

"Just because he's been here forever doesn't mean he's trustworthy-did you see the way he grinned?" Zero inquired, but X didn't respond, even after Zero prodded him a few times. It was quite clear that X had enough of that.


End file.
